Los Angeles Chargers defensive back Derwin James (33) lines up against the Arizona Cardinals during the second half of a preseason NFL football game, Saturday, Aug. 11, 2018, in Glendale, Ariz. (AP Photo/Rick Scuteri)

Los Angeles Chargers running back Detrez Newsome (38) scores a touchdown during the second half of a preseason NFL football game against the Arizona Cardinals, Saturday, Aug. 11, 2018, in Glendale, Ariz. (AP Photo/Rick Scuteri)

Los Angeles Chargers tight end Virgil Green (88) and center Mike Pouncey (53) take the field prior to an preseason NFL football game against the Arizona Cardinals, Saturday, Aug. 11, 2018, in Glendale, Ariz. (AP Photo/Rick Scuteri)

A Los Angeles Chargers fan cheers during the first half of a preseason NFL football game against the Arizona Cardinals, Saturday, Aug. 11, 2018, in Glendale, Ariz. (AP Photo/Rick Scuteri)

Arizona Cardinals head coach Steve Wilks watches during the first half of a preseason NFL football game against the Los Angeles Chargers, Saturday, Aug. 11, 2018, in Glendale, Ariz. (AP Photo/Ross D. Franklin)

GLENDALE, Ariz. — Cardale Jones may very well be a better quarterback than he was a year ago. But if so, it was hard to tell on Saturday night.

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The Chargers put the former fourth-round pick in the starting lineup to open the preseason, giving the big-armed Jones a chance to prove himself worthy of backing up Philip Rivers. It might not be a necessary job: Rivers, 36, has not missed a game since rising to the top of the depth chart back in 2006. No active NFL player — at any position — can match his streak of 192 consecutive regular-season starts.

Still, NFL coaches must prepare for catastrophe, which is what any sort of injury to Rivers would mean for a team hoping to break its three-year playoff drought.

Jones might not represent a sound contingency plan. In a 24-17 loss to Arizona, the 6-foot-5, 250-pound passer looked much like he did a year ago when the Chargers acquired him from Buffalo as a project quarterback. He opened the game with four straight incompletions, including a screen pass that ended up near running back Melvin Gordon’s feet. He put too much juice on a throw to Virgil Green, bouncing it off the tight end’s hand. He took a sack for a loss of 7 yards.

Meanwhile, Rivers watched in street clothes, sitting out an entire preseason opener for the first time in 13 years. Coach Anthony Lynn said the Pro Bowler will play a bit in the Chargers’ next two preseason games against the Seahawks and the Saints.

There were a few bright spots for Jones. He escaped pressure on a 9-yard run that took the Chargers to midfield. His first completion was a 10-yard dart to Artavis Scott, one that gave their team a first down at the Cardinals’ 26-yard line. That drive ended with a 45-yard field goal by Caleb Sturgis, who later missed wide left from 41 yards.

“I thought he missed some throws, but I also thought he made some plays,” Lynn said of Jones. “I have to go back and watch the tape before I make an evaluation on him.”

Jones left the game late in the second quarter having completed 6 of 12 passes for 50 yards. He did much of that work behind the starting offensive line, although not with the team’s full bevy of offensive playmakers. Through five preseason appearances for the Chargers dating to last season, the 25-year-old has produced a thoroughly unimpressive stat line: 42 of 73 for 393 yards, no touchdowns and three interceptions. He has only thrown 11 regular-season passes in his career.

“At some point, I gotta know what we have in Cardale Jones,” said Lynn, who also coached Jones in Buffalo. “He came in this league and has never really been given a legitimate opportunity, in my opinion. I want to give him that opportunity. So I had to see him play tonight.”

There’s still a possibility that Jones, a former national champion at Ohio State, eventually blossoms into a capable NFL quarterback. But earlier this week, offensive coordinator Ken Whisenhunt suggested that the Chargers might prefer someone who can win now. In that case, veteran Geno Smith holds the edge.

Signed in April to a one-year deal, Smith has at least proven 12 times that he can win a regular-season game as a starting NFL quarterback. His deep pass to receiver Geremy Davis was intercepted early in the third quarter, but he tried again with 2:12 left in the period.

It worked. Davis hauled in the 47-yard touchdown, taking the Chargers to the end zone for the first time all night.

Before kickoff at University of Phoenix Stadium on Saturday, the Chargers acknowledged the late Faye Spanos with a moment of silence. The mother of owner Dean Spanos died on Tuesday night at 92 years old.

The Chargers also recognized her with a decal on the back of their helmets, a pink circle with “Faye” printed in black cursive script. Lynn suggested earlier this week that the team might keep the decal on for the entire 2018 season.

Left tackle Russell Okung raised his right fist during the pregame national anthem, as he did last season in protest of police brutality and racial inequality in the United States. … Okung, defensive tackle Brandon Mebane, defensive end Melvin Ingram and tight end Virgil Green represented the Chargers as captains for the pregame coin toss. … In addition to Rivers, Chargers who sat out Saturday included cornerback Casey Hayward, receiver Keenan Allen, receiver Travis Benjamin (shoulder), cornerback Trevor Williams (ankle) and defensive end Joey Bosa (foot). … Backup offensive tackle Sam Tevi suffered what appeared to be a right leg injury, but was walking without assistance after the game. … The Chargers coughed up four turnovers, and cost themselves 155 yards on 15 penalties. “It was just sloppy football,” Lynn said.

Jack Wang covers the Chargers, the latest NFL team to relocate to Los Angeles. He previously covered the Rams, and also spent four years on the UCLA beat, a strange period in which the Bruins' football program often outpaced their basketball team. He is a proud graduate of UC Berkeley, where he spent most of his time in The Daily Californian offices in Eshleman Hall — a building that did not become earthquake-safe until after his time on campus.